Neural circuits encode animal behaviors, and neuroplasticity induces long-lasting changes in neural circuits and animal behaviors. Neural circuits are formed by billions of neurons, which communicate mostly through synapses. Neuroplasticity occurs at the synapse, as neuronal activity modulates synaptic strength through a process known as synaptic plasticity. However, there is no tool to modulate synaptic transmission mimicking synaptic plasticity in vivo. The lack of such a tool makes it difficult to study long-lasting plastic changes in animal behaviors. Here we aim to develop and validate novel molecular tools to modulate excitatory synaptic transmission in the brain. The development and validation of this innovative tool will allow us to modulate neuronal circuits and brain activity so as to elucidate the process of synaptic plasticity and to identify the mechanisms underlying animal behavior. Because hyper- or hypo-activation of synapses causes synaptopathy and because the synapse is modulated by neuronal activity, we may utilize this tool to identify precise circuits/mechanisms that underpin higher-order brain functions including learning and memory, with potential applications to the treatment of neurological disorders. Furthermore, success in this approach may allow us to manipulate distinct properties of synaptic activity including inhibitory or calcium permeability in order to investigate synaptic function in detail. Therefore, the establishment of novel tools to manipulate synaptic activity will impact and stimulate a broad area of research pertaining to brain function.